The East Coast hurricane season, which begins on June 1st, is fast approaching.  The Pacific season starts on May 15th and a named tropical storm, Andres, has already formed.  We know that storm frequency and intensity are increasing with climate change.  This is bad news for all of us who live in possible storm paths.  You are probably also familiar with stories of birds that have been blown off of their traditional course because of a storm and end up being celebrity sightings elsewhere.  However, until this news release, I had never considered the impact of hurricanes on fish such as sharks. 

The new study conducted by researchers at the University of Miami Rosenstiel School of Marine and Atmospheric Science revealed different behaviors by shark species and by location during hurricanes.  Bull sharks (Carcharhinus leucas), nurse sharks (Ginglymostoma cirratum), great hammerheads (Sphyrna mokarran), and tiger sharks (Galeocerdo cuvier) were monitored during Hurricane Matthew in 2016 and Hurricane Irma in 2017.  These were category  5 and category 4 storms, respectively. 

As a reference, bull sharks are around 11 feet in length and weigh about 290 lbs.  Hammerheads are 20 feet long and 500 lbs while nurse sharks average at 13 feet and 730 lbs.  Tipping the scales are the tiger sharks at 14 feet and 1400 lbs.   When reading the following results, weight defines the relative size of the shark more than the length. 

In the study, all four types of sharks were initially found in inshore shallow waters. This was the primary study area.  As the storms approached, most of the relatively smaller sharks left the study area for deeper water.  However, most of the large tiger sharks did not.  Counterintuitively, immediately after the storm, the tiger shark population in the shallows increased.  The research team suspects that the tiger sharks were motivated to be in the area because of the surge in their food supply. They opportunistically fed on fish and invertebrates that died during the storms.  They may be scavengers, but they still like their meat relatively fresh. 



Relative sizes of sharks —

UMiami News Release —

Scholarly publication —

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